Various apparatus has been heretofore used to accumulate enough of a formed tenuous material, such as a plastic or metallic strapping band, a plastic or metallic monofilament, or plastic tubing, such as Tygon tubing, so that the production line need not be halted when feed to a full reel is interrupted to remove and replace the reel.
Presently known to applicant is a looper pit at the end of the product-forming apparatus, into which the product falls. The difficulty with this accumulator system is that it is not practical to dig a deep enough pit and therefore the band begins to pile up on itself and is subject to tangling.
Another accumulator known to applicant (and still in use) consists of a festoon of rolls (as in the paper industry) wherein sets of upper and lower rolls are relatively movable vertically to establish longer paths therebetween for storage of band thereon. This is expensive, requires valuable factory space and is difficult to thread.
Another known prior device required feeding of the formed band into the top of a large container wherein the band is stored layer upon layer, and is cooled by cooling apparatus cooperable with the container. The band is withdrawn from the bottom of the container for coiling on a winder reel. This type of accumulation required a large space-consuming container and was subject to tangling of the band.
Another prior device (still in use) required feeding of the band back and forth onto the entry end of a belt conveyor to store a quantity of band on the conveyor, the band being removed from the exit end of the conveyor and fed to the winder reel. This also requires a great deal of factory space and was subject to tangling of the band, and further offers no real means to cool the band except by exposure to the surrounding atmosphere. Tangling of the band is very undesirable since the tangles sometime do not come out and result in knots. In the case of a knot, the production line must be halted so that the knot may be cut out, and this results in scrapping of the band wound in advance of the knot.
My invention provides an accumulator comprising a tube which occupies very little factory floor space since the tube inclines upwardly from its band receiving end, and has a long portion disposed near or along the roof area of the factory space.
An eductor causes air at high velocity to be drawn inwardly of the tube at the band receiving end so that the band is sucked into the tube and extends throughout a great length thereof. Thus, the band is not only accumulated within the tube but the rush of air through the tube rapidly cools the band to ambient temperature.
Cooling of the band from processing temperature to ambient temperature is very important since the band shrinks as it cools and if it is wound in warm condition on a winder reel, it will shrink as it cools on the reel and will cause camber in the band, or the outer layers may otherwise deform the inner layers.